Knurled socketed screw



Get. 18, 1938. w PURTELL 2,133,465

KNURLED SOCKETED SCREW Filed June 15, 1935 1 1 Wu. \AM A. ELL.

1 VOR.

Patented Oct. 18, 1938 UNITED STATES PATENT OFFICE KNURLED SOCKETED SCREW Application June 15, 1935, Serial No. 26,861

17 Claims.

My invention relates to knurled socketed screws. It has among its objects to provide an improved screw which, while having the advantages of knurling, is also free from the objection to such screws, of permitting the entry of dirt or the like through the knurling at the top thereof and 01' thus producing an unsightly structure. A further object of my invention is to provide an improved knurled cap screw structure whereby it is not only made possible to produce an improved screw, but to produce the knurling thereon very readily and inexpensively in the normal course of manufacture of the screw. These and other objects and advantages of my improvements will, however, hereinafter more fully appear.

In the accompanying drawing, I have shown for purposes of illustration two forms of my improved screw, and have also illustrated my improved method and apparatus in connection with this form of screw.

In the drawing- Figure 1 is a side elevation of my improved screw, a portion of the head also being in section to facilitate illustration;

Fig. 2 is a sectional view on line 22 of Figure '1;

Fig. 3 is a bottom plan view of the head of the screw;

Fig. 4' is a plan view showing one of my improved screws in place in a counter sunk hole receiving the head thereof;

Fig. 5 is a vertical section through a socketing die used in making screws of my improved 5 construction;

Fig. 6 is a side elevation of an unsocketed blank used in making such screws;

Fig. '7 is a vertical sectional view of such a blank being simultaneously knurled and sock- 40 eted in a die of the construction shown in Figure 5, and

Fig. 8 is a sectional view similar to Figure 2 showing a modified form of knurl.

Referring first to the screw shown in Figures 1 to 4, it will be noted that the same is therein a socketed cap screw having a usual head i and shank 2, but in my improved construction also provided on the head i with an upper smooth or unknurled band 3 of the maximum diameter 50 of the head and with a knurled band 4 beneath this band 3, as hereinafter more fully described.

Referring more particularly to the band 3, it will be noted that the same is also of the same diameter as the maximum diameter of the flutes comprising the knurled portion 4, Moreover, it

will be noted that this band 3 is relatively narrow as compared with the knurled band 4. Further, referring to the knurled portion 4, it will be noted that the same comprises outwardly projecting narrow vertical ribs 5 spaced by grooves 6. While not limited thereto, it will also be observed that the cross section of the grooves is herein the same as the projections between the grooves, both herein being of generally triangular cross section. Also, each rib 5 is relatively narrow, yet close enough to its fellow to provide an efiective knurled external surface adapted to be readily and comfortably grasped and turned in the fingers. As shown, the grooves 6 are closed at one end. terminating in inclined surfaces 1 at their upper ends, while the opposite ends of the grooves 6 are open, extending clear through the opposite end of the head I. Thus, it will be observed that an improved knurled screw is provided which has above the knurled portion 4, an improved closing portion 3 which, being of the same diameter as the knurled portion, is adapted to close any aperture which snugly fits the portion 4, and thus to prevent the entry of dirt or the like along the knurling. I

Referring next to the method and apparatus for making my improved screws, attention is directed to the fact that I preferably utilize the preferred method of and apparatus for making cap screws taught in my previous Patent No. 1,978,372, with certain improvements in connection with both whereby the same are adapted to the production of knurled cap screws of the socketed type; it being found that as a result of my improvements, it is made possible to produce knurled cap screws during socketing and without appreciably increasing the expense.

In accordance with my improvements, I prepare, preferably by upsetting in two operations, as taught in my patent mentioned, a headed blank having a tapered head 8, crowned top 9, and elongated shank III as in my prior patent, and, while socketing this blank in a socketing die II and with a socketing punch l2, form my improved knurling including the knurled portion I and the upper smooth closing oil band 3. Referring more particularly to Figure 5, note here that the socketing die II is provided with an inside fluted knurl forming socketing aperture 4. This corresponds in conformation to the knurled portion 4 on the head I of the screw heretofore described and has portions 5' and G thereon corresponding to the portions 5 and 6 on the screw, as well as an inclined portion 1' at the upper ends between 5 and 6 and correspending to portion 1 in the screw. Further, it will be noted that the bottoms of the groove portions 6' in the knurl forming portion of the socket are of the same diameter as a smooth band forming portion i3 whichis above the knurl forming portion and adapted to form the smooth or sealing band 3 on the finished screw, while the rib portions 5' on the portion 4 extend inward to form the grooves 6 in the screw. Also, it will be observed that the socketing die aperture 4' is as usual provided with an extension i4 thereon adapted to receive the shank ill of the blank and that a knockout pin I5 is provided in order to eject the finished screws. Thus, with the blank suitably positioned in the socketing die, when the punch i2 enters the upper end of the blank to socket the same, -i. e., form the socket Iii of the finished screw, I am able simultaneously to form on the screw the smooth upper closing of! rim portion 3 and the lower knurled portion 4, previously described, all in one operation and as the metal displaced by the punch l2 flows laterally from in advance of the punch i2 and is distributed thereby to fill out the die aperture II in the manner disclosed and claimed in my previous patent mentioned.

In Fig. 8, I have illustrated a modified form of knurl which may be used and which presents to the fingers a more smooth knurled surface than that previously described. In this form, it will be noted that the ribs 5 have wide tops while the rooves 6 are substantially wider than the ribs 5. It will of course be evident that this screw will be made by the same general method and apparatus as heretofore described, the socketing die aperture only being changed to conform to the new ribs and grooves.

Here, of course, it will also be understood that, while I have herein shown only a blank and the socketing die and the socketing punch, I contemplate the formation of the blank by upsetting, as previously described in my patent mentioned, and further that I contemplate the use of my improved socketing die and punch in connection with either a separate socketing machine or a mechanism adapted to perform both the upsetting and the socketing operations successively and automatically in the same machine.

As a result of my improvements, it is made possible to produce a socketed cap screw which, while readily manually rotatable with the fingers, is also adapted to close the aperture receiving the head thereof in such manner as to prevent the entry of dirt or the like, and thus, also, to produce a more finished and attractive appearance when the screw is in position in the work. At the same time, it will be observed that it is made possible to knurl this improved screw quickly and easily in the course of the process of socketing the same; all in such manner as to make it possible to produce my improved screw very readily and inexpensively and without requiring any special or additional processes. These and other advantages of my improved construction will, however, be clearly apparent to those skilled in the art.

No claim is made herein to the method and apparatus described herein, the same being claimed in my copending divisional application Serial No. 135,506, filed April l'th, 1937.

While I have in this application specifically described two forms of my improved screw, it will be understood that this disclosure is for purposes of illustration and that modifications thereof may be made without departing from the spirit oi" the invention or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:-

1. A cap screw having a shank and head and having on the latter an upper peripheral closing off portion and a roughened lower peripheral portion closed oil thereby and of substantially the diameter of said closing off portion.

2. A cap screw including a shank and a head having an upper peripheral closing of! band thereon having a circular periphery and a lower roughened band thereon of substantially the diameter of said head and having an irregular periphery closed at its upper end by said band.

3. A cap screw including a shank and a head having an upper annular closing off band thereon of maximum diameter and a lower roughened band thereon closed off by said first mentioned band and of a diameter substantially the same as that of said upper band.

4. A socketed cap screw having a shank and head and having on the latter a smooth upper periphery constituting a closing ofi portion and a knurled lower periphery of substantially the diameter of said closing oif portion and closed off thereby.

5. A socketed cap screw having a shank and head and having on the latter a smooth upper periphery constituting a closing off portion and a knurled lower periphery of substantially the diameter of said closing off portion and closed oil thereby, said upper portion being relatively narrow as compared with said knurled portion.

6-. A socketed cap screw having a shank and head and having on the latter a smooth upper periphery constituting a closing off portion and a knurled lower periphery closed off thereby and of a maximum diameter the same as that of said smooth portion.

'7. A cap screw having a shank and head and having on the latter a smooth upper periphery constituting a closing on portion and a knurled lower periphery closed oiT thereby and of substantially the diameter thereof, said knurled portion comprising spaced parallel ribs merging into the periphery of said closing off portion.

8. A cap screw having a shank and head and having on the latter a smooth upper periphery constituting a closing oi! portion and a knurled lower periphery adapted to be closed off thereby, said knurled portion comprising spaced parallel ribs of substantially the diameter of said smooth upper portion.

9. A cap screw having a shank and head and having on the latter a smooth upper periphery constituting a closing on portion and a knurled lower periphery closed ofi thereby and of substantially the diameter thereof, said knurled portion comprising spaced parallel ribs having wide outer ends.

10. A cap screw having a shank and head and having on the latter a smooth upper periphery constituting a closing oil? portion and a knurled lower periphery closed off thereby and of substantially the diameter thereof, said knurled portion comprising spaced parallel ribs. and grooves between said ribs wider than said ribs.

11. A cap screw having a shank and head and having on the latter a smooth upper periphery constituting a closing ofi portion and a knurled lower periphery closed oil thereby, said knurled portion comprising spaced parallel ribs having closed upper ends and open lower ends.

12. A cap screw having a shank and head and having on the latter a cylindrical upper periphery constituting a closing off portion and a roughened lower periphery adapted to be closed off thereby, said lower periphery having a maximum diameter substantially that of said cylindrical portion.

13. A cap screw having a shank and head and having on the latter a cylindrical upper periphery constituting a closing off portion and a roughened lower periphery adapted to be closed off thereby, said lower periphery having a maximum diameter substantially that oi. said cylindrical portion and said head having tool receiving means in its upper end for effecting turning of the screw after said cylindrical portion enters a countersink of like diameter.

14. A cap screw having a shank and head and having on the latter a cylindrical upper periphery constituting a closing oil portion and a roughened lower periphery adapted to be closed of! thereby, said lower periphery having a maximum diameter substantially that of said cylindrical portion and comprising longitudinal flutes not exceeding in maximum diameter the diameter of said cylindrical portion.

15. A connecting member having an enlarged head provided with a closing ofi portion on one end thereof and a roughened portion closed 05 thereby and oi substantially the same maximum diameter as said closing off portion.

16. A connecting member having an enlarged head provided with a closing off portion on one end thereof and a longitudinally fluted portion closed off thereby and of substantially the same maximum diameter as said closing off portion.

17. A connecting member having an enlarged head provided with a closing off portion on one end thereof and a longitudinally fluted portion closed ofi thereby and of substantially the same maximum diameter as said closing ofl portion, said member also having connecting means on a portion thereof on the opposite side of said fluted portion from said sealing of! portion.

WILLIAM ARTHUR PUR'I'EIL.

CERTIFICATE OF CORRECTION.

Patent No. 2,l53,ii65.

October 18 1958 WILLIAM ARTHUR PURTELL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, second column, line 72, claim 11, after "thereby" and before the comma insert the words and of substantially the diameter thereof; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 27th day 01 December, A. D. 1958.

(Seal) Henry Van Arsdal 9 Acting Commissioner of Patents.

having on the latter a cylindrical upper periphery constituting a closing off portion and a roughened lower periphery adapted to be closed off thereby, said lower periphery having a maximum diameter substantially that of said cylindrical portion.

13. A cap screw having a shank and head and having on the latter a cylindrical upper periphery constituting a closing off portion and a roughened lower periphery adapted to be closed off thereby, said lower periphery having a maximum diameter substantially that oi. said cylindrical portion and said head having tool receiving means in its upper end for effecting turning of the screw after said cylindrical portion enters a countersink of like diameter.

14. A cap screw having a shank and head and having on the latter a cylindrical upper periphery constituting a closing oil portion and a roughened lower periphery adapted to be closed of! thereby, said lower periphery having a maximum diameter substantially that of said cylindrical portion and comprising longitudinal flutes not exceeding in maximum diameter the diameter of said cylindrical portion.

15. A connecting member having an enlarged head provided with a closing ofi portion on one end thereof and a roughened portion closed 05 thereby and oi substantially the same maximum diameter as said closing off portion.

16. A connecting member having an enlarged head provided with a closing off portion on one end thereof and a longitudinally fluted portion closed off thereby and of substantially the same maximum diameter as said closing off portion.

17. A connecting member having an enlarged head provided with a closing off portion on one end thereof and a longitudinally fluted portion closed ofi thereby and of substantially the same maximum diameter as said closing ofl portion, said member also having connecting means on a portion thereof on the opposite side of said fluted portion from said sealing of! portion.

WILLIAM ARTHUR PUR'I'EIL.

CERTIFICATE OF CORRECTION.

Patent No. 2,l53,ii65.

October 18 1958 WILLIAM ARTHUR PURTELL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, second column, line 72, claim 11, after "thereby" and before the comma insert the words and of substantially the diameter thereof; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 27th day 01 December, A. D. 1958.

(Seal) Henry Van Arsdal 9 Acting Commissioner of Patents. 

